Research on Dynamic Response Characteristics and Condition Indicators of Gear Wear Fault

Abstract

Gear wear fault belongs to a typical incipient fault. In order to monitor gear wear status, the mechanism and condition indicators of gear wear fault are studied. The influence of gear wear on dynamic parameters such as time-varying meshing stiffness and unloaded static transmission error is quantitatively studied: the Archard wear model is used to calculate the wear depth of tooth surface, and the non-uniform wear distribution along the tooth profile is obtained. Time-varying mesh stiffness is calculated by the potential energy method, and the influence of gear wear on the amplitude of mesh stiffness is evaluated. Gear wear is equivalent to the tooth profile deviation, and the influence of gear wear on the unloaded static transmission error is calculated. The dynamics model of gear transmission is established by means of lumped parameter method and the dynamic response characteristics of gear wear fault is verified by fatigue life test of two stage spur gear. The results show that gear wear affects the meshing frequency and its harmonics. Meanwhile, the sidebands of meshing frequency and its harmonics are mainly composed of rotational frequencies, which changes obviously with the increase of wear depth. Based on the obtained dynamic response characteristics of wear fault, four condition indicators based on the meshing frequency sideband of vibration signal are constructed, which are sensitive to the change of wear state. The effectiveness and robustness of condition indicators are verified by simulation and experiments.